1. Field of the Invention
The present invention relates to an assist grip which is provided in a vehicle and the like.
2. Description of the Related Art
An assist grip is a member which is mounted in a vehicle and the like to be used as a handrail for passengers (for example, refer to Japanese Laid-Open Patent Publication No. 6-190866). There is a kind of assist grip that includes two or more divisional bodies which are separately formed and unitarily assembled.
There are two types of divisional bodies of the assist grip, one of which is formed by partitioning the assist grip in a longitudinal direction, and the other of which is formed by partitioning the assist grip in a direction across the longitudinal direction. Hereinafter, the divisional body formed by partitioning the assist grip in the longitudinal direction will be referred to as a longitudinal divisional body, and the assist grip having the longitudinal divisional bodies will be referred to as a longitudinal division type assist grip. Also, the divisional body formed by partitioning the assist grip in the direction across the longitudinal direction will be referred to as a latitudinal divisional body, and the assist grip having the latitudinal divisional bodies will be referred to as a latitudinal division type assist grip.
In the latitudinal division type assist grip, a junction portion between the divisional bodies is formed in the direction across the longitudinal direction of the assist grip. Accordingly, when compared to the longitudinal division type assist grip, the latitudinal division type assist grip is weak in a load applied in the direction across the longitudinal direction of the assist grip. When the assist grip is used as a handrail for passengers, a load is applied to the assist grip in the direction across the longitudinal direction of the assist grip. Accordingly, the load bearing capacity required at the junction portion between the divisional bodies in the latitudinal division type assist grip is larger than the longitudinal division type assist grip.
In the latitudinal division type assist grip, if an outer periphery of the junction portion between the latitudinal divisional bodies is received in an outer cylinder member, which is made of a material having high stiffness and has a cylindrical shape, the load bearing capacity at the junction portion can be increased. In the latitudinal division type assist grip, the latitudinal divisional bodies can be joined to each other by adhesion, screw coupling, fitting, or the like. Considering the load bearing capacity and the simplicity of manufacturing, it is preferable to join the latitudinal divisional bodies to each other by fitting. In this case, in order to cover the fitting portion between the latitudinal divisional bodies with the outer cylinder member, as shown in FIG. 10, latitudinal divisional bodies 100 and 200 are respectively inserted into an outer cylinder member 300 through both ends of the outer cylinder member 300, and the latitudinal divisional body 100 and the latitudinal divisional body 200 are fitted to each other inside the outer cylinder member 300.
In order to securely fit the latitudinal divisional body 100 and the latitudinal divisional body 200 to each other, it is preferable to enlarge the fitting portion between the latitudinal divisional bodies (X portion in FIG. 11). In order to sufficiently secure the load bearing capacity of the assist grip, it is needed to increase the diameters of the thinnest portions of the respective latitudinal divisional bodies 100 and 200 (base portions 101 and 102, Y and Z portions in FIG. 11). However, as described above, because the assist grip is used as a handrail for passengers, an outer diameter and an inner diameter of the outer cylinder member 300 cannot be increased so largely. Accordingly, it is impossible to increase all of the fitting portion X of the latitudinal divisional body 100 and the latitudinal divisional body 200, the outer diameter Y of the base portion 101, and the outer diameter Z of the base portion 102. As a result, it is difficult to provide a latitudinal division type assist grip having a sufficient load bearing capacity.